diff options
Diffstat (limited to 'lib/Analysis/MemorySSA.cpp')
| -rw-r--r-- | lib/Analysis/MemorySSA.cpp | 9 |
1 files changed, 7 insertions, 2 deletions
diff --git a/lib/Analysis/MemorySSA.cpp b/lib/Analysis/MemorySSA.cpp index f57d490ce96e..b38c0c4f1439 100644 --- a/lib/Analysis/MemorySSA.cpp +++ b/lib/Analysis/MemorySSA.cpp @@ -258,13 +258,18 @@ static ClobberAlias instructionClobbersQuery(MemoryDef *MD, if (const IntrinsicInst *II = dyn_cast<IntrinsicInst>(DefInst)) { // These intrinsics will show up as affecting memory, but they are just - // markers. + // markers, mostly. + // + // FIXME: We probably don't actually want MemorySSA to model these at all + // (including creating MemoryAccesses for them): we just end up inventing + // clobbers where they don't really exist at all. Please see D43269 for + // context. switch (II->getIntrinsicID()) { case Intrinsic::lifetime_start: if (UseCS) return {false, NoAlias}; AR = AA.alias(MemoryLocation(II->getArgOperand(1)), UseLoc); - return {AR == MustAlias, AR}; + return {AR != NoAlias, AR}; case Intrinsic::lifetime_end: case Intrinsic::invariant_start: case Intrinsic::invariant_end: |